472 UTOBATES. gb 22° 31' oh mb 39 40 oc bb 68 6 Oo' db 90 o oo" w ' 136 12 o’o” mm 79 20 na gg' 45 2 nc BIG. 465. 51° 29' nn 117° 44' 53 58 nn" 19 49 62 7 nn 121 38 77 2 uc 43 26 107 56 uu' 79 11 31 8 uu" 29 43 60 49 uu" 86 52 FIG. 466. Combinations, cbwe, cbame.h, cbwvdg, cbamghlen.o. The races b deeply striated parallel to their intersections with a. JLwms. Twin-face h. co = 59° 20', an = 120° 40', hi{ = 61° 20' Cleavage, a, 5 distinct, especially the latter; c, indistinct, fracture imperfect conchoidal...uneven. Opaque. Lustre imperfect metallic, passing into adamantine on the faces and cleavages, and into resinous on the surface of fracture Iron- black, brownish, greyish-black. Streak dark reddish-brown or brownish-black, n = 6 -0. g = 6-32...6-39. Conducts elec tricity. Infusible before the blowpipe. With borax forms a blackish- green. glass which does not become opaque in an interrupted blast. Soluble m bisulphate of potash. Is not acted upon by Analyses of niobite a, b from Rabenstein, streak black, Q — 6-39, 0 streak dark reddish-brown, g = 5-7, all by H. Rose, streak dark, g = 6 078, d by Awdejew, streak dark reddish-brown g = 5-976, * by Jacobson, / from North America by Mangnac:— b c d e f 81-34 79-68 80‘64 7973 77‘30 13-89 15-10 15-33 1477 1300 3-77 4'65 4'65 4‘77 9-60 0-19 0-121 0-10 050 0-10 0-12/ 010 1-51 — trace trace o - 2i — — Middletown in Connecticut, streak ^iob. pelop. acids Protox. iron Protox. mangan Oxide of tin Ox. copper . Lime . Analyses of niobite fr 817 14-; 3-8 0-4 o-i